PRDI-BFI and RIZ homology domain containing proteins (PRDM) play a key role in cell differentiation and proliferation.Most members of the PRDM gene family are tumor suppressor genes which involved in tumorigenesis and abnormal expression in a variety of tumors.Aberrant DNA methylation often silences these genes,which may occur in the early stage of tumor,Cancer can be reversed by demethylation,which provides a new way for cancer treatment.